Hypercortisolemia is a physiologically important feature of the stress response and occurs in normal aging. The P.I. has found reversible memory impairment after four days of placebo-controlled dexamethasone treatment in normal adults. These results suggest that endogenous GC exposure may be responsible for DMP impairment during a variety of stress physiologic or pathophysiologic conditions in humans. This application proposes to test the cognitive effects of cortisol in adult humans.